Thread: Working Backwards with Simultaneous Equations

I am currently studying simultaneous equations, but there is a particular type of problem that I cannot figure out. For example: In a money bank there is £11.40, made up of 35 coins. All the coins are either 30ps or 50ps. The example is just made up, but how would you work this out using simultaneous equations?

let x = number of one type of coin

y = number of the other type of coin

x + y = total number of coins

x(worth of this type of coin) + y(worth of the other type of coin) = total worth

thank you. I worked this out just before you posted, but you have reinforced this method.